Febrifugine and isofebrifugine derived from Chinese hydrangea are known to have strong activities against tropical malarial protozoan.
The chemical structures of febrifugine and isofebrifugine, known to show such strong activities against malarial protozoan, were reported to be represented by Formulas (A0) and (B0): 
Although the activity of these febrifugine compounds have been known from old times as active ingredients of Chinese medicines such as “JOSAN” practical isolation and utilization of these compounds have been difficult due to their rarity in nature, and efforts to develop an efficient method for synthesizing them under gentle conditions have not been successful.
Therefore, extensive investigations have been desired, from the viewpoint of efficient synthesis of febrifugines, including the synthesis of analogues, and the view point of the stereochemistry which enables the exertion of bioactivity.
Thus, the objective of the present invention is to thoroughly reinvestigate the basis of such strong activity against malarial protozoan in relation with its stereochemistry, to identify actual substances which exhibit extremely strong activity against tropical malarial protozoan, and to establish a total synthetic route which allows efficient large scale synthesis, by overcoming such conventional circumstances.